is Compiling CMI with mvn/gradle Illegal?

[Outfit8TSB]

i compiled a mcmmo plugin with maven, since i was a developer who used buildtools.
but is compiling CMI source code when CMI Become open source(the same thing i did to mcmmo), a illegal action to do and count as a Piracy/cracking?
here are those Open-source premium plugins. from SpigotMC wiki.
is compiling all of these with build tool and source code even a illegal?

A
AACBungeeConnect (Inactive Resource)
Actions
Adapt
Advanced Achievements (Inactive Resource)
AdvancedEnchantments
AdvancedMobArena
AirDrops (Outdated Since v1.0)
AntiCheatAddition
AsyncWorldEdit
Auction House¹

B
BattleCards
BeautyQuests Expansion
BetterEnd Premium (EOL (end-of-life)) (Inactive Resource)
BetterRTP-Addons
BetterSleeping Premium
BookVerify
Boosters
boosCooldowns
BossShopPro
BountyHunters Premium (Repository Archived)
Build My Text! (Outdated Since v1.0.0)
BungeeUtilisalsX

C
CakeTwitch
Cartographer 2
Citizens
ClosedBlocksElevator (Outdated Since v1.0.0)
COM-Warfare (Legacy/Premium) (Free Since v2.15.4¹)
Companies
Cosmin
CraftBook (Moved to Bukkit)
CrashClaim¹
creative-glyphs
CustomArchaeology
CustomCrafting

D
DailyShop
DamageIndicator (Outdated Since v1.1.7)
Daytime
DeliveryBoard
DuoAuth (Free Since v1.1.9¹) (Inactive Resource)
Dwellin (Outdated Since v1.0) (Proprietary Library)

E
EcoArmor
EcoBits
EcoBosses
EcoCrates
EcoEnchants
EcoItems
EcoJobs
EcoPets
EcoQuests
EcoShop
EcoSkills
EnchantmentsEnhancePro (Inactive Resource) (Repository Archived)
EnchantmentSlots
EnderVaults
ExcellentShop

F
FactionRankup (Inactive Resource)
FancyCraftingPlus (Inactive Resource)
FancyWaystones¹ (Outdated Since v1.0.45)
Farms
Fatality (Outdated Since v1.6)
FordEnchants (Inactive Resource)
FreakyEnchants (Outdated Since v1.1.9) (Inactive Resource)

G
GalacticStandardLibrary
Games In The Box
GriefDefender¹ (Outdated Since v1.5.10)
GSitPro (Free version¹ is the same)
Guilds¹
GriefPreventionTP

H
HCF Plus (Outdated Since v1.18.9c)
HMCCosmetics
HMCLeaves
HMCWraps
Houses (Outdated Since v2.8) (Inactive Resource)
HuskSync
HuskTowns
Hynick
HyperDrive

I
ImmortalLogin
Influencers
Investment (Outdated Since v1.5.2)
IridiumChunkBusters
Iridium Enchants
Iris World Gen¹

J
JustAnimations

K
Kauri Anticheat (Free Since v2.18.1¹) (Inactive Resource)

L
LagAssist (Outdated Since v2.29.0)
LandLord Dynmap
Lib's Disguises
LotteryPool+ (Outdated Since v1.1.2)

M
MarketPoint
Markets¹
MaskedGUI
mcMMO
mcMMO Classic
MCPerks¹
McRPG
Minespades
MiPhone
MissileWars (Free Since v4.1.2¹)
MMOInventory¹
MobStats
Multi Character
MysticTotem
M0-SafeCreative (Outdated Since v1.0.0)

N
Negativity
NightMarket

O
ObsidianDestroyer (Free Since v4.4.17¹)
Oraxen

P
Panilla
PatternPro (Outdated Since v1.0.1)
PermGUI2 (Outdated Since v2.0.1)
Per World Plugins
PictureAds
PlasmaEnchants
PlayerRadios
PlayerSkills2
PlayerVaultsX
PlotSquared v6
Private Mines¹ (Outdated Since v1.6.4)
Public Crafting Tables
Pwing Races

Q
Quake (Free Since v2.1.5¹)
QualityArmory Vehicles 2
QuickTransfer

R
Rankup
React¹
RealisticVillagers
RedisChat
Reforges
Residence¹
RolCards (Free Since v1.2.3¹) (Outdated Since v1.2.1)
Rotator¹ (Outdated Since v1.0.6)
RoseLoot
RPGHorses
RPG Inventory (Free Since v2.3.2¹) (Inactive Resource)
RPGRegions

S
Schematic Brush Reborn 2
ServerCinematics (Inactive Resource)
ServerSelectorX Premium
Shops
SilkSpawnersShopAddon
SimplePets
SkillAPI Premium (Inactive Resource)
Skills Pro
SkinOverlay
SkywarsReloaded Extension
SpaceChat (Inactive Resource)
StackResize (Outdated Since v1.2.1)
StaffProtect¹
StatTrackers
Spawners
Stonks (Outdated Since v1.0.7)
Sudden Death
SuperAuth
SuperManager
SystemInfo

T
Talismans
TerraformGenerator Premium
Throwables
Tools+ (Outdated Since v2.1.3)
Towny Elections (GitHub)
Trade Audit
Trade Proxy
Trade+ (Outdated Since v3.84.5)
TrMenu Premium (Moved to GitHub)
Tweakin
Twitter4Spigot (Outdated Since v1.0.2) (Repository Archived)

U
Ultima's Hats
UltimateHammer (v2 Branch)
UltimateJobs
UltimateParty (Outdated Since v1.2.11)
UltimateShop-Premium
Ultra Minions (Inactive Resource)
Ultra SkyWars (Inactive Resource)
uQueue

V
VenturaCalendar (Outdated Since v2.6.0)
VoidChest (Outdated Since May 29, 2019)

W
WorldSchematics3 (Outdated Since v3.3)

X
Xray

Y

Z

[Addon] ChestShopLimiter (Inactive Resource)
[Duels Extension] ArenaRegen
[Duels Extension] Leaderboards
¹